1. Field of the Invention
The present invention relates to combustible gas detectors, and more particularly to a miniature combustible gas detector operable within a limited space.
2. Description of the Related Art
The risk of an explosion due to a combustible gas at an industrial work site has always existed. Conventional gas detectors offer one possible preventive measure in the hopes of curtailing this risk. Conventional gas detectors, however, are impractical for a few reasons; first, they are too large for workers to carry to such sites, and secondly, their production costs are prohibitive for mass production. That is, portability and economy were never considerations in their design.
A need therefore exists for a combustible gas detector, which is miniaturized, lightweight and affordable. The miniaturization, however, should not mitigate the performance of the detector.
In accordance with the present invention, a miniaturized combustible gas detector is provided in which both the sensor and the processing circuitry are configured in a common housing, the detector comprising: a control circuit for controlling the operation of the gas detector, operational software for operating the detector via the control circuit; an armor case providing electromagnetic protection for the control circuit; a clip installed at one side of the armor case for clipping the detector on a worker""s uniform, a power switch for operating the detector; power supply means for supplying a direct current power for operating the control circuit; and an LED display for displaying the operational status of the detector.
The control circuit further includes a sensor for sensing a combustible gas when the power switch is turned on; a sensor driving circuit for driving said sensor, a signal conditioner for amplifying and converting the signals sensed by said sensor; an A/D converter for converting analog signals received from the signal conditioner into digital signals, a CPU for processing the digital signals under control of said operational software; an EEPROM for storing the data processed by said CPU and for storing said operational software; and an alarm for providing an alarm indication depending on the result processed by said CPU.
A method for operating the combustible gas detector according to the present invention generally comprises the steps of: driving the combustible gas detector; initializing the combustible gas detector; conducting a self-diagnostic of the combustible gas detector upon completion of the initialization step; activating a measurement mode upon completion of the conducting step; confirming whether a key-in is activated after said measurement mode has been activated; activating a sub-menu in the event said key-in is activated; otherwise activating a power saving mode in the event said key-in is not activated.
The detector of the present invention is advantageously designed so that it may be conveniently carried and worn with ease.
According to one aspect of the invention, the detector is constructed such that once a user turns on the detector it cannot be turned off for safety reasons. That is, the detector is continuously operable for 24 hours under battery power, preferably of an alkaline variety.